Whipple procedure for duodenal gastrointestinal stromal tumors: A report of two cases

Abstract

Introduction and importance

Gastrointestinal stromal tumors (GIST) are rare neoplasms that can grow anywhere along the GI tract. They comprise only 0.1 % to 3 % of all gastrointestinal tumors, and approximately 30 % of GISTs are malignant. They exhibit variable clinical presentations, ranging from incidental findings to symptomatic presentations such as gastrointestinal bleeding, abdominal pain, abdominal mass, or obstruction. Duodenal gastrointestinal stromal tumors are among the rarest subtypes, accounting for less than 4 % of all GISTs but up to 21 % of the resected ones.

Case presentation

We report two cases of duodenal GIST (dGIST) treated with the Whipple procedure. The first patient, a 73- year old woman, presented with dizziness, and lightheadedness. The patient had severe anemia requiring blood transfusions. Imaging revealed a mass with fistula formation. Subsequent endoscopy with biopsy confirmed the diagnosis of GIST. The second patient, a 48-year-old woman, presented with lightheadedness, melena and epigastric abdominal pain. Laboratory investigations revealed severe anemia. Urgent upper endoscopy revealed an ulcerated submucosal duodenal mass. Imaging demonstrated mass near the junction of the second and third part of the duodenum.

Clinical discussion

The surgical approach for GIST is usually influenced by tumor size, site, histopathological findings and overall risk assessment. Nevertheless, unlike other subtypes of GISTs, surgical management of duodenal GISTs poses unique challenges due to ongoing controversies regarding the most appropriate surgical approach.

Conclusion

Diagnosis of GIST can be challenging and is usually influenced by the presenting symptoms. The cornerstone of management in GIST is complete tumor resection with negative margins.

Highlights

• •Duodenal gastrointestinal stromal tumors (dGISTs) are rare, accounting for less than 4 % of all GISTs.
• •The Diagnosis of duodenal GIST can be difficult due to their variable clinical presentations.
• •The surgical approach to duodenal GISTs remains a topic of debate.
• •Surgical options include limited resection and the Whipple procedure.
• •The Whipple procedure proved to be an effective treatment in our cases, with an uneventful postoperative course.

1. Introduction

GISTs are rare neoplasms that originate from the interstitial cells of Cajal [1]. Approximately 30 % of all GISTs are malignant and most commonly spread hematogenously to the liver and peritoneal cavity. Lymphatic spread, on the other hand, is rarely observed [2,3]. GISTs can occur anywhere along the digestive tract. The stomach is the most common site for GISTs, accounting for approximately 60 % of cases. Duodenal GISTs only comprise less than 4 % of all GIST cases [4].

The mainstay of management of GISTs is complete surgical resection with an essential goal of achieving negative margins and ensuring no tumor capsule rupture. The presentation of GIST is usually misleading and can often resemble a broad spectrum of other conditions, which leads to misdiagnosis and inappropriate management. Duodenal GISTs usually lie in confined areas with complex anatomy and intricate relationships to adjacent essential structures. Therefore, the optimal procedure for dGIST remains a topic of debate [5,6]. In this case report, we present two cases of duodenal GIST treated with Whipple procedure. By describing these cases, we aim to contribute to the existing literature on the clinical characteristics, diagnostic challenges, and management considerations of GISTs in diverse anatomical locations within the GI tract.

2. Methods

This work has been reported in line with the SCARE 2025 criteria.

3. Case presentations

3.1. Case (1)

A 73-year-old woman with a history of hypothyroidism, congestive heart failure, and prior cholecystectomy presented with dizziness. Her hemoglobin levels were 5 g/dL, requiring multiple transfusions. On physical examination, a 3–4 cm firm abdominal mass was noted.

An initial CT showed a 10 × 11 × 7 cm heterogeneous mesenteric mass with necrosis and lymphadenopathy. Biopsy via endoscopic ultrasound revealed features consistent with GIST and immunohistochemical staining was positive for c-KIT and DOG1.One month later, abdominal CT (Fig. 1A, B) revealed an increase in the size of the tumor measuring 13 × 13 × 8 cm with necrosis, central air, and calcific foci. A fistula was also detected between the mass lesion and the third part of the duodenum. Multiple perilesional lymph nodes were present, and the main feeder of the mass was identified as the hypertrophied gastroduodenal artery, which compressed the superior mesenteric artery anteriorly and medially.

Fig. 1.

A, 1B: (Contrast-enhanced CT (axial [A] and coronal [B] views) of case 1 showing a large heterogeneous duodenal mass measuring 13 × 13 × 8 cm with central necrosis, calcific foci, intralesional air, and fistula formation between the mass and the third part of the duodenum.

Two trials of transarterial embolization failed to control the bleeding and the patient subsequently underwent Whipple procedure with Roux en Y reconstruction. During surgery, an ulcerated localized mass measuring 12 × 9 × 6 cm was found between the third and fourth part of the duodenum and the jejunum as well. No postoperative complications were reported. Histopathological testing exhibited a low-grade G1 GIST of spindle cell type with a mitotic rate of 3 per 50 HPF. The tumor was unifocal, localized to the duodenum, of high-risk assessment, and with multiple areas of necrosis. All surgical margins tested negative with the closest margin being 2 mm from the retroperitoneum. All 15 lymph nodes resected were confirmed to be negative.

3.2. Case (2)

A 48-year-old woman with a history of schizophrenia, hypertension, and prior hysterectomy with bilateral salpingo-oophorectomy presented with fatigue, melena and shortness of breath. Her hemoglobin level was 4.3 g/dL. She was admitted as a case of upper gastrointestinal bleeding and given 10 units of packed RBCs. An urgent upper endoscopy revealed an ulcerated submucosal duodenal mass near the ampulla of Vater. A Staging CT (Fig. 2, 2B) demonstrated an intramural exophytic enhanced hypervascularized mass near the junction of the second and third part of the duodenum without signs of obstruction. The mass is closely adherent to the posterior-inferior edge of the pancreatic head.

Fig. 2.

A, 2B: (Contrast-enhanced CT (axial [A] and coronal [B] views) of Case 2 showing a hypervascular exophytic mass measuring 4 × 3.5 × 2.2 cm at the junction of the second and third parts of the duodenum, closely adherent to the pancreatic head.)

The patient underwent a Whipple procedure with Roux-en-Y reconstruction with an uneventful postoperative course. Intraoperatively, a well-localized 4 × 3.5 × 2.2 cm duodenal tumor with no local invasion was seen at the second part of the duodenum below the head of the pancreas. The tumor was located in the submucosa and extended to the subserosal space, measuring about 4 × 3.5 × 2.2 cm with a mitotic index of 0 per 50 HPF, consistent with a low-risk tumor.

4. Discussion

4.1. Epidemiology

Gastrointestinal stromal tumors (GISTs) are rare tumors and comprise only 1 % of all GI tumors with an estimated incidence of 10–20 cases per million populations [7]. They can arise anywhere along the GI tract with the stomach being the most common site. The average age at diagnosis is 50–65 years [8,9]. In these case reports, the age of the first and second cases was respectively higher and lower than the average age at presentation (Table 1). Duodenal GISTs are usually small in size compared to GISTs found in more common sites. The median size of dGISTs is 4 cm. The first patient had a large tumor sized approximately 12 cm. DGISTs account for less than 4 % of all GISTs. Nevertheless, up to 30 % of all duodenal tumors are GISTs [9]. Therefore, GIST should be highly suspected in any patient presenting with duodenal mass. DGISTs most commonly occur in the second part of the duodenum followed by the third and fourth, parts, respectively [6].

Table 1.

Comparison of clinical and pathological features between the two presented cases of duodenal gastrointestinal stromal tumors (GISTs) and the average/typical presentation reported in the literature.

GISTs	Average range/typical presentation	Case 1	Case 2
Age of presentation	50–65	73	48
Initial workup	Presentation dependent	Computed tomography	Upper endoscopy
Site	Stomach	Between D3 & D4	Between D2 & D3
Size	dGIST: 4 cm	12 × 9 × 6 cm	4 × 3.5 × 2.2 cm
Fistulization	Rare	Present	Absent
Biopsy & final diagnosis	Only 50 % have a preoperative diagnosis	Pre-operative	Post-operative
Mitotic rate	–	3 mitoses per 50 HPF	0 mitoses per 50 HPF
Risk assessment	–	High-risk	Low-risk

4.2. Diagnosis

The diagnosis of GISTs might be challenging, as patients might be asymptomatic in up to 18 % of cases or present with a wide range of symptoms [10]. In our cases, both patients presented with severe anemia, but the initial presentation influenced a different initial diagnostic workup. For instance, the first patient had a palpable abdominal mass and underwent a CT scan followed by an endoscopy, while the second patient had melena and underwent an emergent endoscopy first with a subsequent CT scan.

CT with oral and IV contrast is a highly useful diagnostic method for detecting primary GIST and metastatic lesions. CT is also helpful in the characterization and differentiation between primary and recurrent GISTs with respect to tumor size, growth pattern, and homogeneity. Therefore, CT scans can be indirectly used to predict the outcome and the prognosis of the disease. GISTs are classified into three groups based on size: small (<5 cm), intermediate (5–10 cm), and large or extensive (>10 cm). [11]

Endoscopic findings of GIST usually show a submucosal protruding mass with intact mucosa. However, bleeding and ulceration are not uncommon. Preoperative biopsy might be challenging as these tumors are usually soft and friable. Therefore, biopsy should be avoided in patients with easily resectable tumors as this can increase the risk of tumor seeding. In literature, only about 50 % of patients had a definitive histological diagnosis before surgery [12]. In the first patient, a preoperative biopsy was obtained and a histological diagnosis of GIST was confirmed before surgery. Conversely, the second patient was diagnosed postoperatively. The definitive diagnosis of GIST is made by pathological testing of the tumor tissue. Immunohistochemically, GISTs are characterized by their positive expression of c-KIT (CD117) in over 95 % of cases [14].

4.3. Complications

Aggressive findings and signs of malignancy are more commonly seen in larger tumors and recurrent disease [11]. CT imaging of the first case showed a tumor that was located between D3 and D4 with a large size of 13x13x8 cm. It also demonstrated areas of necrosis, central air, and the presence of a fistula between the mass lesion and the third part of the duodenum. Fistulization is a fairly rare but serious complication of GISTs. Large tumors have a higher risk of developing a fistula compared to smaller ones [13]. In the second case, the tumor was located between D2 and D3 in unfavorable proximity to the ampulla of Vater with a smaller size.

4.4. Management

Surgery remains the cornerstone of management for individuals with primary GIST with no signs of metastasis. Additionally, it should be the first-line treatment if the tumor is technically respectable and carries an acceptable risk of morbidity. The primary objective during surgery is to achieve complete gross resection, with emphasis on preserving an intact pseudocapsule and obtaining negative microscopic margins. Extensive surgery may be required, particularly for poorly situated tumors. [14] As for the case of duodenal GISTs, it can be either managed by limited resection when feasible and safe or by a Whipple procedure [10]. Both patients in our report underwent Whipple procedure, justified by tumor proximity to critical structures, size and high mitotic index. In Case 1, limited resection was not feasible due to a very large (13 cm), necrotic, and fistulizing tumor compressing the superior mesenteric artery. In Case 2, although the tumor was smaller, it was located at the D2–D3 junction and closely adherent to the pancreatic head and ampulla, where segmental duodenectomy risked ductal injury and inadequate margins. While limited resections or pancreas-sparing duodenectomies are suitable for small dGISTs situated away from the ampulla, neoadjuvant imatinib may facilitate tumor downsizing, potentially enabling less extensive surgery. Use of neoadjuvant imatinib has been associated with reduced intraoperative blood loss, shorter operative time, shorter hospital stay, and lower short-term morbidity and readmission rates [10]. However, both of our patients were acutely symptomatic and required definitive resection. In accordance with NCCN and ESMO guidelines, the Whipple procedure was the most appropriate choice to achieve complete tumor clearance in both cases [17,18].

Transarterial embolization (TAE) is considered a viable option for managing certain types of gastrointestinal tumors such as GISTs. Embolization serves as an alternative option for managing bleeding, particularly in elderly patients who face increased risk for postoperative morbidity due to advanced age or overall poor health conditions. TAE proves to be a beneficial method for managing GIST-related GI bleeding including life-threatening bleeding as well as preoperative measures for tumor shrinkage or as a palliative management. In some studies, TAE has demonstrated a clinical success of up to 90 % in controlling GI bleeding from GISTs. [15] In the first case, two TAE attempts were performed due to high operative risk from heart failure. While the initial attempt showed partial success, in the second trial the celiac trunk was found to be severely tortuous, which prevented successful cannulation and rendered surgery inevitable.

4.5. Prognosis

Tumor location, size, mitotic rate, mutational status and the occurrence of tumor rupture significantly attributes to survival rates and mortality. Nevertheless, tumor size and mitotic rate are the two most commonly acknowledged risk factors. In the literature, there is limited evidence regarding the prognosis of duodenal GISTs [9]. However, gastric GISTs tend to have more favorable outcomes compared to small intestinal GISTs with similar size and mitotic rate. Finally, due to its high recurrence rate GISTs should be closely followed up with abdominal CT after surgical resection [16]. Standard surveillance for duodenal GISTs typically includes contrast-enhanced CT scans of the abdomen and pelvis every 3–6 months or annually depending on risk assessment [17]. Although imatinib was recommended for the first case due to high-risk stratification, both patients were lost to follow-up and were unable to initiate treatment after being discharged back to Gaza shortly after surgery because of the ongoing conflict.

5. Conclusion

GISTs are rare neoplasms that can grow anywhere along the GI tract. Approximately 30 % of all GISTs are malignant. Therefore, it is necessary to maintain a high level of suspicion to achieve the best outcome possible for patients. In conclusion, the characteristics and locations of GISTs help determine the surgical approach and risk assessment. This case report highlights the importance of recognizing and managing these rare neoplasms and highlights the Whipple procedure as the preferred surgical approach in such complex cases. Additionally, the significance of this case lies in its demonstration of the diagnostic challenges of dGIST and the importance of a multidisciplinary approach involving radiology, pathology, and surgical intervention. Surgical resection with negative margins remains the gold standard treatment. Post-operative monitoring is important as GISTs are associated with a high recurrence rate.

Consent for publication

Written informed consent was obtained from the patient for the publication of their clinical details and any accompanying images. All identifying information has been anonymized to protect patient confidentiality. A copy of the signed consent form is available for review by the Editor-in-Chief upon request.

Ethical approval and consent to participate

This case report was conducted in accordance with the ethical standards of our institutional policies and the principles outlined in the Declaration of Helsinki. According to our institutional guidelines, case reports are exempt from formal ethical committee approval.

Funding

The authors received no financial support for the research, authorship, and/or publication of this report.

Declaration of competing interest

The authors declare that they have no conflicts of interest to disclose.